Five years after the events of Dragon Ball, martial arts expert Goku is now a grown man married to his wife Chi-Chi, with a four-year old son named Gohan. While attending a reunion on Turtle Island with his old friends Master Roshi, Krillin, Bulma and others, the festivities are interrupted when a humanoid alien named Raditz not only reveals the truth behind Gokuu's past, but kidnaps Gohan as well.